“…At present, there are many methods such as discrete Fourier transform (DFT) [5,6], wavelet-based methods [7,8], total leastsquares estimation of signal parameters via rotational invariance techniques (TLS-ESPRITs) [9], Hilbert transform (HT) [10], empirical mode decomposition (EMD) [11], Prony [12,13], recursive LS (RLS) [14], blind source separation [15], and stochastic subspace identification (SSI) [16], which are based on the measurement of trajectory data, to analyse low-frequency oscillation.…”